C++ User Input
C++ User Input
You have already learned that cout is used to output (print) values. Now we will use cin to get user input.
cin is a predefined variable that reads data from the keyboard with the extraction operator (>>).
In the following example, the user can input a number, which is stored in the
variable x. Then we print the value of x:
Example
int x;
cout << "Type a number: "; // Type a number and
press enter
cin >> x; // Get user
input from the keyboard
cout << "Your number is: " << x;
// Display the input value
Run example »
Good To Know
cout is pronounced "see-out". Used for output, and uses the insertion operator (<<)
cin is pronounced "see-in". Used for input, and uses the extraction operator (>>)
Creating a Simple Calculator
In this example, the user must input two numbers. Then we print the sum by calculating (adding) the two numbers:
Example
int x, y;
int sum;
cout << "Type a number: ";
cin >> x;
cout << "Type another number: ";
cin >>
y;
sum = x + y;
cout << "Sum is: " << sum;
Run example »
There you go! You just built a basic calculator!
Complete <iostream> Reference
Tip: Both cin and cout belongs to the <iostream> library,
which is short for standard input /
output
streams. For a complete reference of <iostream> objects along with detailed information, go to our C++ iostream Reference.
